Drafting pen with cleaning wire



DRAFTING.PEN WITH CLEANING WIRE Oct. 20, 1970 E. BoK 3,535,050

DRAFTING PEN WITH CLEANING WIRE Filed Oct. 24, 1968 2 Sheets-Sheet 2 INVEroR United States Patent O 3,535,050 DRAFTING PEN WITH CLEANING WIRE Edward Bok, Falls Church, Va., assignor to Dike, Inc., Washington, D.C., a corporation of the District of Columbia i' Filed Oct. 24, 1968, Ser. No. 770,251 Int. Cl. B43k 1/10 U.S. Cl. 401-260 9 Claims ABSTRACT F THE DISCLOSURE Stylographic drafting pens, particularly a drafting pen equipped with a cleaning wire which is reciprocable in and out of a scribing channel while simultaneously venting the ink reservoir to the atmosphere.

CROSS REFERENCE TO RELATED APPLICATIONS Drafting pen, Ser. No. 760,923, filed Sept. 19, 1968, now abandoned. Drafting pen, Ser. No. 762,844, led Sept. 26, 1968. Drafting pen, Ser. No. 762,878, filed Sept. 26, 1968, now abandoned.

In the earlier applications, the stylographic drafting pen included a Weighted cleaning wire extending from the area of the ink reservoir through the capillary passage, the weight being seated at the bottom of the ink reservoir. The cleaning wire was reciprocated longitudinally in the scribing channel by a shaking or jerking movement of the pen unseating the weight within the reservoir. The reservoir was vented by a downward `movement of a valve stem through the top of the ink reservoir.

According to the present construction, the weight is eliminated from the cleaning wire and a valve stem extends through the vent in the top of the reservoir to the cleaning wire. Thus, a single longitudinal reciprocation may induce cleaning movement of the cleaning wire in the scribing channel or capillary passage, While simultaneously venting the reservoir.

BACKGROUND yOF THE INVENTION (1) Field of the invention A principal shortcoming in contemporary stylographic drafting pens is the dried-ink clogging of the ink capillary passageway or scribing channel which extends from the ink reservoir to the pen tip end. This scribing channel is usually constructed from hardened metal or sapphire tube, the end of which contacts the drafting paper, as ink is fed axially thereof. Caking of dried ink in the capillary passage can totally obstruct or at least seriously interfere with ink flow. A cleaning wire is usually mounted, so that it extends through the capillary passage and is secured to a weight seated within the ink reservoir. By shaking of the drafting instrument the weight is unseated from its seat within the ink reservoir and the cleaning wire is more or less actuated Within the capillary passage.

(2) Description of the prior art In the prior art devices there was no positive means for cleaning the ink capillary passage of dried ink nor was there a positive means for venting of the ink reservoir, so as to eliminate the undesirable reservoir vacuum induced by ink flow and facilitate flow through the capillary passage.

3,535,050 Patented Oct. 20, 1970 The most pertinent prior art is: Schmidt, 1,447,632; Wallace, 2,214,494; Buschle, 2,805,645; Cholet, 2,878,- 783; Kovacs, 2,891,512.

The prior art devices have included mechanisms for extending and retracting the needle within the pen tip. However, the degree of extension or retraction has been slight and there has not been a positive means for clearing the capillary passage. See Buschle (2,805,645.) In this device the crank shaft 6 and guide rod 3 are provided for reciprocating needle A within the pen tip 1. Reciprocation of the needle is limited to the extent of the offset 6 in the crank shaft and there is not provided a positive means for automatically retractng the needle.

See also Cholet (2,878,783.) Here needle 23 is simply used as a sealing mechanism and there is not provided any means for longitudinally reciprocating needle 23 within the pen tip to the extent that crystallized ink may be completely removed. Also there is not provided any means for automatically withdrawing the needle as it is desired to write.

In the patent application (Ser. No. 697,433), entitled Drafting Pen and led by applicant herein Jan. 12, 1968, a drafting pen is described whereby it is possible to have the drafting pen placed on the sheet at an angle which is most suitable for the draftsman. This pen included the combination of a pen tip and a guide or support which rested on the drafting sheet. Consequently, the pen tip was supported at an angle to the paper and the radial position of the pen tip with respect to the barrel was fixed.'

In some drafting work this more expensive construction is not required, especially if the quality of the drawn lines are of not too great importance. The possibility of supporting a drafting pen in a given radial position and with only the pen tip resting upon the drafting papers provides a big advantage over the existing drafting pens.

Furthermore, conventional stylographic drafting pens and also the drafting pens as are described in the aforementioned patent application (Ser. No. 697,433), make use of a vent construction to the ink cartridge which is positioned in the bottom part of the pen underneath the ink cartridge. See Pat. No. 2,891,512. In this type vent there are the disadvantages of an easy clogging with dried ink in the vent opening and the leakage of ink through the opening in the pen tip.

Wallace (2,214,494) is typical of the weighted cleaning wire in the prior art, inducing reciprocatory action number 13a by a jerking movement.

Kovacs (2,891,512) induces reciproeatory movement of cleaning wire 25 by pressure upon plunger 22. However, there is not simultaneously induced a venting action nor is there shown the capability of extending the cleaning wire beyond the tip of the tubular writing nozzle 26.

SUMMARY OF THE INVENTION According to the present invention, the drafting pen is comprised of a housing enclosing an ink reservoir having a pen tip with tubular point communicating with the ink reservoir via a capillary passage. An integrated valve stem extends through the vent in the reservoir and is connected within the reservoir to a cleaning wire which extends into the capillary passage. By longitudinal actuation of the valve stern in either direction, the reservoir is vented while the cleaning wire reciprocates within the cleaning channel. In rest position the cleaning wire is balanced within the capillary passage and the reservoir vent is sealed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view of a stylographic writing pen according to the invention, showing its cleaning wire as part of the vent stem, which stem is in its rest position;

FIG. 2 is a vertical sectional view of the writing pen according to FIG. 1, showing the vent stem in its lowest or extended position;

FIG. 3 is a vertical sectional view of the writing pen according to FIGS. 1 and 2, showing the vent stem in its top or retracted position;

FIG. 4 is a transverse sectional View of the writing pen taken along section lines 4-4 of FIG. 1;

FIG. 5 is a transverse sectional View of the writing pen taken along section lines 5-5 of FIG. 1;

FIG. 6 is an enlarged fragmentary sectional view of the writing nib with the cleaning wire in rest position, as is indicated in FIG. 1;

FIG. 7 is an enlarged fragmentary sectional view of the writing nib with the cleaning wire in lowest or eX- tended position, as is indicated in FIG. 2;

FIG. 8 is an enlarged fragmentary sectional view of the writing nib with the cleaning wire in top or retracted position, as is indicated in FIG. 3;

FIG. 9 is a fragmentary sectional view of a modified stylographic writing pen, showing another vent system for the ink reservoir with the vent stem closing the vent opening in its rest position;

FIG. 10* is a fragmentary sectional View of the modified stylographic Writing pen according to FIG. 9, showing the vent stern in its lowest or extended position with also closed vent opening; and

FIG. 11 is a fragmentary sectional View of the modified stylographic writing pen according to FIGS. 9 and 10, showing the vent stem in its top or retracted position with the vent opened.

DESCRIPTION `OF THE PREFERRED EMBODIMENTS In FIG. 1 writing pen 10 is shown, which pen mainly consists of barrel 12, ink reservoir 14, writing nib 16 and the pen tip 18. Cleaning wire 20, which extends through pen tip 18, is as an integral extension of vent stem 22.

Lower compression spring 24 is positioned above ink reservoir 14 between the Vent screw 30 and the stem holder 26. Top compression spring 32 located in the top of barrel 12 above the stem holder 26, and provides together with lower compression spring 24 the longitudinally balanced rest position of stem holder 26, so long as no longitudinally compressive forces are applied via knob 28 protruding through barrel 12.

Ink reservoir 14 is provided with ear 36 having ink supply opening 34. Ear 36 protrudes through the recessed side wall 40 of barrel 12 via opening 38. A milled ller ring 42, which manually is rotatable vertically within recess 44 of barrel 2, normally provides a sealing off of the opening 34. However, if the filler opening 46 in this iiller ring 42 is rotated from the sealing position shown in FIG. 4 to register with opening 34, the filling of the ink reservoir 14 with ink 62 is possible.

Ink reservoir 14 may consist of a iexible material such as plastic or nylon, so that during the assembly of the pen 10, ink reservoir 14 can be deformed to such an extent as to enable ear 36 of this ink reservoir to be forced tted within barrel 12 opening 38. This force fitting thereby provides an angular locking of the ink reservoir 14 within barrel 12.

With the succeeding fitting of writing nib 16 in its longitudinally correct place within ink reservoir 14, upper extension 48 of this non-flexible nib 16 moves axially inward of ink reservoir 14 towards the ink passage 34. As a result in the completely assembled pen, as threaded plug 50 longitudinally locks a writing nib 16 within barrel 12, the median section of the ink reservoir 14 adjacent ear 36 no longer can be deformed and ear 36 under pressure rests firmly against the inside of filler ring 42. As illustrated in FIG. 4, this pressurized sealing ear 36 within opening 38 also radially locks pen nib 16 and pen tip 18 with inclined bottom 66 in iixed radial position.

In FIGS. l and 6y stern holder 26 is shown in mid or rest position, with the cleaning wire 20 balanced longitudinally within pen tip 18. In this rest position vent stem 22 top 52 seals oi vent opening 54 within vent screw 30. With the aid of vent screw 30, which is threaded within reservoir top, a precise longitudinal setting of vent screw 30 with respect to vent stem 22 is obtained.

In FIGS. 2 and 7 the lowest extended position of stem holder 26 is achieved by manually pushing down the knob 28 against the pressure of spring 24, whereby cleaning needle 20 partly extends beyond pen tip 18, cleaning ink passage 58. In the extended position, vent opening 54 in vent screw 30 is open for venting of ink reservoir 14.

In FIG. 5 annular ink chamber 56 is shown, from which chamber during writing with pen 10 ink 62 ows through the ink passage 58 or scribing channel to the pen tip bottom `66.

Knob 28 is used to retract stem holder 26 against the force of the compression spring 32 to its top or retracted position with the position of the cleaning wire 20y within ths pen tip 18, as shown in FIGS. 3 and 8. In this retracted position of stem holder 26 the vent opening 54 is again sealed oif by means of the stem top 52.

In lFIGS. 9, 10, and 1l modified writing pen 10 is provided with another type of vent stem 22. Stern valve 52' may be constructed as an integral part of stem holder 26', so as to abut reclined diameter extension 60 cleaning wire 20. Extension 60 has a smaller diameter than stern Valve 52.

In FIG. 9 the rest or (mid) position of stem holder 26' is shown and in FIG. l0l is shown lowest or extended position of stem holder 26. In both positions the stem valve 52 seals vent opening 54.

In FIG. 11 stern holder 26 is manually brought to its top or retracted position, opening vent opening 54 so that venting of the ink reservoir can take place. The tips retracted positions of the stem holders 26 and 26 can also be obtained by manually bringing the knob 28 to its lowest position, then loosen knob 28, so that compression spring 24 starts the upward movement of stem 26 against the relatively weak pressure of spring 32.

I claim:

1. A drafting pen comprising:

(A) a holder;

(B) a reservoir, having a vent, supported in said holder;

(C) a pen tip secured to said holder and communicating with said ink reservoir via a capillary passage;

(D) a cleaning wire reciprocably positioned within said capillary passage; and

(E) stem means extending through said vent and contacting said cleaning wire, whereby reciprocation of said stem vents said reservoir while said cleaning wire reciprocates within said capillary passage.

2. A drafting pen as in claim 1, said pen tip extending axially inwardly of said reservoir as a longitudinal support.

3. A drafting pen as in claim 2, said stem further including:

(i) an override housing secured to the top end of Said stem and supported in said holder adjacent said reservoir and (ii) a compression spring interposed between said reservoir and said override housing.

4. A drafting pen as in claim 3, said reservoir further including:

(i) a vent valve top having an axial passage with said stem extending from said override piece through said axial passage and said compression spring encircling said stem above said vent valve.

5. A drafting pen comprising:

(A) an open-ended holder;

(B) a reservoir, having a vent, supported in said holder; (C) a pen tip secured to said holder and communicating with said ink reservoir via a capillary passage; (D) a cleaning Wire reciprocably positioned within said capillary passage, so as to be extensible beyond said pen tip end;

(E) stern means extending through said vent and contacting said cleaning wire, whereby reciprocation of said stem vents said reservoir and reciprocates said cleaning wire within said capillary passage, said stem further including:

(i) an override housing secured to said stem top above said reservoir;

(ii) a compression assembly interposed between said override and said holder; and

(iii) a tab extending radially outwardly from said override housing through said holder.

6. A drafting pen as in claim 6, said pen tip including:

(i) a tubular writing point communicative with said reservoir; and

(ii) a collar engaging the open end of said holder and compressing said pen tip with respect to said reservoir.

7. A drafting pen as in claim 6, said reservoir having an ink filling passage extending laterally through said holder.

8. A drafting pen as in claim 7, a valving portion of said stem extending through said vent being of greater diameter than a portion of said stem extending into said reservoir to said cleaning wire.

9. A drafting pen as in claim 8, said stem in its upper portion being of smaller diameter than said valving portion.

References Cited UNITED STATES PATENTS LAWRENCE CHARLES, Primary Examiner 

